1. Field of the Invention
This invention relates to sprockets more particularly to non-metallic sprockets used in wastewater treatment facilities.
2. Description of Related Art
Sludge collectors are commonly used in wastewater treatment plants to scrape the settled sludge from the bottom of the settling tank and also to skim floating waste off the surface of the wastewater. These sludge collectors typically include a number of sludge flights which are usually elongated members that extend the width of the tank. The ends of the flights are connected to conveyor chains which carry the flights in a circuit lengthwise along the bottom of the tank and back over the surface of the water to perform the scraping and skimming functions. The tanks are typically made of concrete and the supporting shafts with bearings and locking collars support the transmission sprockets which in turn power the conveyor chain and flight systems.
Sprockets in a sludge collector generally consist of three types. The first may be the keyseated and setscrewed driving or transmission type. The second may be the loose or free wheeling type. Further, the third may be the setscrewed only type.
Referring now to FIG. 1, there is shown a prior art sprocket 10 having a plurality of teeth 12 used in connection with wastewater treatment facilities. The sprocket 10 comprises a bore 14 having a keyway 16. The sprocket 10 is formed of two sections 18 and 20. The sections 18 and 20 are joined at the line 22 via bolts 24 and locknuts 25. The bolts 24 may be secured in flanges 26 in each of the sections 18 and 20.
The bolts 24 and locknuts 25 utilized are typically made of stainless steel. Due to the fact that stainless steel is a relatively soft material, the bolt threads may become destroyed by the locknuts when disassembling the sprockets for maintenance or replacement. As a result, it is desirable to have a fastener for securing the sections 18 and 20 not subjected to damage and expensive replacement which may be reused.